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Feng Y, Lu H, Whiteway M, Jiang Y. Understanding fluconazole tolerance in Candida albicans: implications for effective treatment of candidiasis and combating invasive fungal infections. J Glob Antimicrob Resist 2023; 35:314-321. [PMID: 37918789 DOI: 10.1016/j.jgar.2023.10.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Revised: 10/07/2023] [Accepted: 10/22/2023] [Indexed: 11/04/2023] Open
Abstract
OBJECTIVES Fluconazole (FLC) tolerant phenotypes in Candida species contribute to persistent candidemia and the emergence of FLC resistance. Therefore, making FLC fungicidal and eliminating FLC tolerance are important for treating invasive fungal diseases (IFDs) caused by Candida species. However, the mechanisms of FLC tolerance in Candida species remain to be fully explored. METHODS This review discusses the high incidence of FLC tolerance in Candida species and the importance of successfully clearing FLC tolerance in treating candidiasis. We further define and characterize FLC tolerance in C. albicans. RESULTS This review identifies global factors affecting FLC tolerance and suggest that FLC tolerance is a strategy of C. albicans response to FLC damage whose mechanism differs from FLC resistance. CONCLUSIONS This review highlights the significance of the cell membrane and cell wall integrity in FLC tolerance, guiding approaches to combat IFDs caused by Candida species..
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Affiliation(s)
- Yanru Feng
- Department of Pharmacy, Shanghai Tenth People's Hospital, School of Medicine, Tongji University, Shanghai, China
| | - Hui Lu
- Department of Pharmacy, Shanghai Tenth People's Hospital, School of Medicine, Tongji University, Shanghai, China
| | | | - Yuanying Jiang
- Department of Pharmacy, Shanghai Tenth People's Hospital, School of Medicine, Tongji University, Shanghai, China.
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Trivedi A, Maheshwari R, Tarnow-Mordi WO, Saxena N. Lactoferrin for the postoperative management of term neonates after gastrointestinal surgery. Cochrane Database Syst Rev 2023; 5:CD012218. [PMID: 37233609 PMCID: PMC10215284 DOI: 10.1002/14651858.cd012218.pub2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
BACKGROUND Neonates who have undergone gastrointestinal surgery are particularly susceptible to infectious complications in the postoperative period. This may be due in part to disruption of the integrity of the gut and its altered intestinal microflora. Lactoferrin is a whey protein found in milk and is an important innate mammalian defence mechanism. Lactoferrin has been reported to have antimicrobial and anti-inflammatory properties. It has also been reported to help establish a healthy gut microflora and aid in the intestinal immune system. Lactoferrin supplementation has been reported to decrease sepsis in preterm infants. There may be a role for lactoferrin to reduce the incidence of sepsis, thus reducing morbidity and mortality and improving enteral feeding in postoperative term neonates. OBJECTIVES The primary objective of this review was to evaluate the efficacy of administering lactoferrin on the incidence of sepsis and mortality in term neonates after gastrointestinal surgery. The secondary objective was to assess the impact of administering lactoferrin on time to full enteral feeds, the intestinal microflora, duration of hospital stay, and mortality before discharge in the same population. SEARCH METHODS The Cochrane Neonatal Information Specialist searched the Cochrane Central Register of Controlled Trials (CENTRAL), Ovid MEDLINE, Embase Ovid, CINAHL, the WHO ICTRP and ClinicalTrials.gov trials registries. The date of the last search was February 2023. There were no restrictions to language, publication year or publication type. We checked references of potentially relevant studies and systematic reviews. SELECTION CRITERIA We planned to include randomised controlled trials that studied infants born at 37 or more weeks of gestation who had one or more episodes of gastrointestinal surgery within 28 days of birth, and compared administration of lactoferrin with a placebo. DATA COLLECTION AND ANALYSIS We used standard Cochrane methodological procedures. We planned to use the GRADE approach to assess the certainty of evidence for each outcome. MAIN RESULTS We identified no published randomised controlled studies that assessed the efficacy of lactoferrin for the postoperative management of term neonates following gastrointestinal surgery. AUTHORS' CONCLUSIONS There is currently no evidence available from randomised controlled trials to show whether lactoferrin is effective or ineffective for the postoperative management of term neonates after gastrointestinal surgery. There is a need for randomised controlled trials to be performed to assess the role of lactoferrin in this setting.
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Affiliation(s)
- Amit Trivedi
- Grace Centre for Newborn Care, The Children's Hospital at Westmead, Westmead, Australia
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Sugimura T, Seo T, Terasaki N, Ozaki Y, Rikitake N, Okabe R, Matsushita M. Efficacy and safety of breast milk eye drops in infants with eye discharge. Acta Paediatr 2021; 110:1322-1329. [PMID: 33098117 DOI: 10.1111/apa.15628] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 10/14/2020] [Accepted: 10/16/2020] [Indexed: 11/28/2022]
Abstract
AIM Breast milk (BM) contains various protective components, such as immunoglobulins, lactoferrin, lysozyme, oligosaccharides and immune cell subsets. We evaluated the effectiveness of BM eye drops in infants with eye discharge in a randomised controlled study. METHODS Subjects were breastfed infants aged ≤180 days, with eye discharge. We randomly assigned patients to receive eye drops of BM or sodium azulene sulphonate hydrate 0.02% ophthalmic solution (OS). The patients received drop of BM or OS for 7 days. Improvement score of eye discharge in the groups was compared using a non-inferiority test. RESULTS The number of patients improved eye discharge was 119/155 (76.8%) and 119/157 (75.8%) in BM and OS groups, respectively. There were no significant differences between groups. The improvement score in eye discharge was 1.76 ± 0.91 in the BM group and 1.71 ± 0.96 in the OS group. The BM group was considered non-inferior to the OS group. CONCLUSIONS This study demonstrated that BM is no less effective than OS in infants with eye discharge aged ≤6 months. The results suggested that the use of breast milk as eye drops could be considered as a first-line treatment for infants aged ≤6 months with eye discharge.
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Affiliation(s)
- Tetsu Sugimura
- Department of Pediatrics and Allergology Sugimura Children's Medical Clinic Chikugo City Japan
| | - Tomoko Seo
- Department of Pediatrics Green Woods Children's Clinic Okazaki City Japan
| | - Nami Terasaki
- Department of Pediatrics and Allergology Sugimura Children's Medical Clinic Chikugo City Japan
| | - Yukiko Ozaki
- Department of Pediatrics Kurume University School of Medicine Kurume City Japan
| | - Noriko Rikitake
- Department of Pediatrics and Allergology Sugimura Children's Medical Clinic Chikugo City Japan
| | - Rumiko Okabe
- Department of Pediatrics Kurume University School of Medicine Kurume City Japan
| | - Masami Matsushita
- Department of Pediatrics Kurume University School of Medicine Kurume City Japan
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Sienkiewicz M, Jaśkiewicz A, Tarasiuk A, Fichna J. Lactoferrin: an overview of its main functions, immunomodulatory and antimicrobial role, and clinical significance. Crit Rev Food Sci Nutr 2021; 62:6016-6033. [PMID: 33685299 DOI: 10.1080/10408398.2021.1895063] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Lactoferrin (LF), a glycoprotein found in mucosal secretions, is characterized by a wide range of functions, including immunomodulatory and anti-inflammatory activities. Moreover, several investigations confirmed that LF displays high effectiveness against multiple bacteria and viruses and may be regarded as a potential inhibitor of enveloped viruses, such as presently prevailing SARS-CoV-2. In our review, we discuss available studies about LF functions and bioavailability of different LF forms in in vitro and in vivo models. Moreover, we characterize the potential benefits and side effects of LF use; we also briefly summarize the latest clinical trials examining LF application. Finally, we point potential role of LF in inflammatory bowel disease and indicate its use as a marker for disease severity.
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Affiliation(s)
- Michał Sienkiewicz
- Department of Biochemistry, Faculty of Medicine, Medical University of Lodz, Lodz, Poland
| | - Andrzej Jaśkiewicz
- Institute of Food Technology and Analysis, Faculty of Biotechnology and Food Sciences, Lodz University of Technology, Lodz, Poland
| | - Aleksandra Tarasiuk
- Department of Biochemistry, Faculty of Medicine, Medical University of Lodz, Lodz, Poland
| | - Jakub Fichna
- Department of Biochemistry, Faculty of Medicine, Medical University of Lodz, Lodz, Poland
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5
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Evaluation of Direct and Cell-Mediated Lactoferrin Gene Therapy for the Maxillofacial Area Abscesses in Rats. Pharmaceutics 2021; 13:pharmaceutics13010058. [PMID: 33406760 PMCID: PMC7823524 DOI: 10.3390/pharmaceutics13010058] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 12/11/2020] [Accepted: 12/31/2020] [Indexed: 12/19/2022] Open
Abstract
Resistance to antibacterial therapy requires the discovery of new methods for the treatment of infectious diseases. Lactoferrin (LTF) is a well-known naïve first-line defense protein. In the present study, we suggested the use of an adenoviral vector (Ad5) carrying the human gene encoding LTF for direct and cell-mediated gene therapy of maxillofacial area phlegmon in rats. Abscesses were developed by injection of the purulent peritoneal exudate in the molar region of the medial surface of the mandible. At 3-4 days after phlegmon maturation, all rats received ceftriaxone and afterward were subcutaneously injected around the phlegmon with: (1) Ad5 carrying reporter gfp gene encoding green fluorescent protein (Ad5-GFP control group), (2) Ad5 carrying LTF gene (Ad5-LTF group), (3) human umbilical cord blood mononuclear cells (UCBC) transduced with Ad5-GFP (UCBC + Ad5-GFP group), and (4) UCBC transduced with Ad5-LTF (UCBC + Ad5-LTF group). Control rats developed symptoms considered to be related to systemic inflammation and were euthanized at 4-5 days from the beginning of the treatment. Rats from therapeutic groups demonstrated wound healing and recovery from the fifth to seventh day based on the type of therapy. Histological investigation of cervical lymph nodes revealed purulent lymphadenitis in control rats and activated lymphatic tissue in rats from the UCBC + Ad5-LTF group. Our results propose that both approaches of LTF gene delivery are efficient for maxillofacial area phlegmon recovery in rats. However, earlier wound healing and better outcomes in cervical lymph node remodeling in the UCBC + Ad5-LTF group, as well as the lack of direct exposure of the viral vector to the organism, which may cause toxic and immunogenic effects, suggest the benefit of cell-mediated gene therapy.
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Brilhante RSN, Costa ADC, Pereira VS, Fernandes MR, de Oliveira JS, Rodrigues AM, Camargo ZP, Pereira-Neto WDA, Sidrim JJC, Rocha MFG. Antifungal activity of deferiprone and EDTA against Sporothrix spp.: Effect on planktonic growth and biofilm formation. Med Mycol 2020; 59:myaa073. [PMID: 32838409 DOI: 10.1093/mmy/myaa073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 07/28/2020] [Accepted: 08/18/2020] [Indexed: 11/14/2022] Open
Abstract
The present study evaluated the antifungal activity of the chelators deferiprone (DFP) and ethylenediaminetetraacetic acid (EDTA) and their effect on biofilm formation of the S. schenckii complex. Eighteen strains of Sporothrix spp. (seven S. brasiliensis, three S. globosa, three S. mexicana and five Sporothrix schenckii sensu stricto) were used. Minimum inhibitory concentration (MIC) values for EDTA and DFP against filamentous forms of Sporothrix spp. ranged from 32 to 128 μg/ml. For antifungal drugs, MIC values ranged from 0.25 to 4 μg/ml for amphotericin B, from 0.25 to 4 μg/ml for itraconazole, and from 0.03 to 0.25 μg/ml for terbinafine. The chelators caused inhibition of Sporothrix spp. in yeast form at concentrations ranging from 16 to 64 μg/ml (for EDTA) and 8 to 32 μg/ml (for DFP). For antifungal drugs, MIC values observed against the yeast varied from 0.03 to 0.5 μg/ml for AMB, 0.03 to 1 μg/ml for ITC, and 0.03 to 0.13 μg/ml for TRB. Both DFP and EDTA presented synergistic interaction with antifungals against Sporothrix spp. in both filamentous and yeast form. Biofilms formed in the presence of the chelators (512 μg/ml) showed a reduction of 47% in biomass and 45% in metabolic activity. Our data reveal that DFP and EDTA reduced the growth of planktonic cells of Sporothrix spp., had synergistic interaction with antifungal drugs against this pathogen, and reduced biofilm formation of Sporothrix spp. LAY SUMMARY Our data reveal that iron chelators deferiprone and ethylenediaminetetraacetic acid reduced the growth of planktonic cells of Sporothrix spp. as well as had synergistic interaction with antifungal drugs against this pathogen and reduced biofilm formation of Sporothrix spp.
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Affiliation(s)
- Raimunda Sâmia Nogueira Brilhante
- Specialized Medical Mycology Center, Postgraduate Program in Medical Microbiology, Department of Pathology and Legal Medicine, Federal University of Ceará. Rua Cel. Nunes de Melo, 1315 - Rodolfo Teófilo - CEP: 60430-275, Fortaleza, Ceará, Brazil
| | - Anderson da Cunha Costa
- Specialized Medical Mycology Center, Postgraduate Program in Medical Microbiology, Department of Pathology and Legal Medicine, Federal University of Ceará. Rua Cel. Nunes de Melo, 1315 - Rodolfo Teófilo - CEP: 60430-275, Fortaleza, Ceará, Brazil
| | - Vandbergue Santos Pereira
- Specialized Medical Mycology Center, Postgraduate Program in Medical Microbiology, Department of Pathology and Legal Medicine, Federal University of Ceará. Rua Cel. Nunes de Melo, 1315 - Rodolfo Teófilo - CEP: 60430-275, Fortaleza, Ceará, Brazil
| | - Mirele Rodrigues Fernandes
- Specialized Medical Mycology Center, Postgraduate Program in Medical Microbiology, Department of Pathology and Legal Medicine, Federal University of Ceará. Rua Cel. Nunes de Melo, 1315 - Rodolfo Teófilo - CEP: 60430-275, Fortaleza, Ceará, Brazil
| | - Jonathas Sales de Oliveira
- Specialized Medical Mycology Center, Postgraduate Program in Medical Microbiology, Department of Pathology and Legal Medicine, Federal University of Ceará. Rua Cel. Nunes de Melo, 1315 - Rodolfo Teófilo - CEP: 60430-275, Fortaleza, Ceará, Brazil
| | - Anderson Messias Rodrigues
- Cellular Biology Division, Department of Microbiology, Immunology and Parasitology, Federal University of São Paulo. Rua Botucatu, 862, 6th floor, Medical Sciences Building, CEP: 04023-062, São Paulo, São Paulo, Brazil
| | - Zoilo Pires Camargo
- Cellular Biology Division, Department of Microbiology, Immunology and Parasitology, Federal University of São Paulo. Rua Botucatu, 862, 6th floor, Medical Sciences Building, CEP: 04023-062, São Paulo, São Paulo, Brazil
| | - Waldemiro de Aquino Pereira-Neto
- Specialized Medical Mycology Center, Postgraduate Program in Medical Microbiology, Department of Pathology and Legal Medicine, Federal University of Ceará. Rua Cel. Nunes de Melo, 1315 - Rodolfo Teófilo - CEP: 60430-275, Fortaleza, Ceará, Brazil
| | - José Júlio Costa Sidrim
- Specialized Medical Mycology Center, Postgraduate Program in Medical Microbiology, Department of Pathology and Legal Medicine, Federal University of Ceará. Rua Cel. Nunes de Melo, 1315 - Rodolfo Teófilo - CEP: 60430-275, Fortaleza, Ceará, Brazil
| | - Marcos Fábio Gadelha Rocha
- Specialized Medical Mycology Center, Postgraduate Program in Medical Microbiology, Department of Pathology and Legal Medicine, Federal University of Ceará. Rua Cel. Nunes de Melo, 1315 - Rodolfo Teófilo - CEP: 60430-275, Fortaleza, Ceará, Brazil
- Postgraduate Program in Veterinary Sciences, College of Veterinary Medicine, State University of Ceará. Av. Dr. Silas Munguba, 1700, Campus do Itaperi, CEP: 60714-903, Fortaleza, Ceará, Brazil
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Lactoferrin Is Broadly Active against Yeasts and Highly Synergistic with Amphotericin B. Antimicrob Agents Chemother 2020; 64:AAC.02284-19. [PMID: 32094132 PMCID: PMC7179636 DOI: 10.1128/aac.02284-19] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Accepted: 02/15/2020] [Indexed: 12/23/2022] Open
Abstract
Lactoferrin (LF) is a multifunctional milk protein with antimicrobial activity against a range of pathogens. While numerous studies report that LF is active against fungi, there are considerable differences in the level of antifungal activity and the capacity of LF to interact with other drugs. Here we undertook a comprehensive evaluation of the antifungal spectrum of activity of three defined sources of LF across 22 yeast and 24 mold species and assessed its interactions with six widely used antifungal drugs. LF was broadly and consistently active against all yeast species tested (MICs, 8 to 64 μg/ml), with the extent of activity being strongly affected by iron saturation. LF was synergistic with amphotericin B (AMB) against 19 out of 22 yeast species tested, and synergy was unaffected by iron saturation but was affected by the extent of LF digestion. LF-AMB combination therapy significantly prolonged the survival of Galleria mellonella wax moth larvae infected with Candida albicans or Cryptococcus neoformans and decreased the fungal burden 12- to 25-fold. Evidence that LF directly interacts with the fungal cell surface was seen via scanning electron microscopy, which showed pore formation, hyphal thinning, and major cell collapse in response to LF-AMB synergy. Important virulence mechanisms were disrupted by LF-AMB treatment, which significantly prevented biofilms in C. albicans and C. glabrata, inhibited hyphal development in C. albicans, and reduced cell and capsule size and phenotypic diversity in Cryptococcus Our results demonstrate the potential of LF-AMB as an antifungal treatment that is broadly synergistic against important yeast pathogens, with the synergy being attributed to the presence of one or more LF peptides.
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8
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Roszkowiak J, Jajor P, Guła G, Gubernator J, Żak A, Drulis-Kawa Z, Augustyniak D. Interspecies Outer Membrane Vesicles (OMVs) Modulate the Sensitivity of Pathogenic Bacteria and Pathogenic Yeasts to Cationic Peptides and Serum Complement. Int J Mol Sci 2019; 20:ijms20225577. [PMID: 31717311 PMCID: PMC6888958 DOI: 10.3390/ijms20225577] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 11/04/2019] [Accepted: 11/05/2019] [Indexed: 12/22/2022] Open
Abstract
The virulence of bacterial outer membrane vesicles (OMVs) contributes to innate microbial defense. Limited data report their role in interspecies reactions. There are no data about the relevance of OMVs in bacterial-yeast communication. We hypothesized that model Moraxella catarrhalis OMVs may orchestrate the susceptibility of pathogenic bacteria and yeasts to cationic peptides (polymyxin B) and serum complement. Using growth kinetic curve and time-kill assay we found that OMVs protect Candida albicans against polymyxin B-dependent fungicidal action in combination with fluconazole. We showed that OMVs preserve the virulent filamentous phenotype of yeasts in the presence of both antifungal drugs. We demonstrated that bacteria including Haemophilus influenza, Acinetobacter baumannii, and Pseudomonas aeruginosa coincubated with OMVs are protected against membrane targeting agents. The high susceptibility of OMV-associated bacteria to polymyxin B excluded the direct way of protection, suggesting rather the fusion mechanisms. High-performance liquid chromatography-ultraviolet spectroscopy (HPLC-UV) and zeta-potential measurement revealed a high sequestration capacity (up to 95%) of OMVs against model cationic peptide accompanied by an increase in surface electrical charge. We presented the first experimental evidence that bacterial OMVs by sequestering of cationic peptides may protect pathogenic yeast against combined action of antifungal drugs. Our findings identify OMVs as important inter-kingdom players.
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Affiliation(s)
- Justyna Roszkowiak
- Department of Pathogen Biology and Immunology, Institute of Genetics and Microbiology, University of Wroclaw, 51-148 Wroclaw, Poland; (J.R.); (G.G.); (Z.D.-K.)
| | - Paweł Jajor
- Department of Pharmacology and Toxicology, Faculty of Veterinary Medicine, Wroclaw University of Environmental and Life Sciences, 50-375 Wroclaw, Poland;
| | - Grzegorz Guła
- Department of Pathogen Biology and Immunology, Institute of Genetics and Microbiology, University of Wroclaw, 51-148 Wroclaw, Poland; (J.R.); (G.G.); (Z.D.-K.)
| | - Jerzy Gubernator
- Department of Lipids and Liposomes, Faculty of Biotechnology, University of Wroclaw, 50-383 Wroclaw, Poland;
| | - Andrzej Żak
- Ludwik Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Science, 53-114 Wroclaw, Poland;
| | - Zuzanna Drulis-Kawa
- Department of Pathogen Biology and Immunology, Institute of Genetics and Microbiology, University of Wroclaw, 51-148 Wroclaw, Poland; (J.R.); (G.G.); (Z.D.-K.)
| | - Daria Augustyniak
- Department of Pathogen Biology and Immunology, Institute of Genetics and Microbiology, University of Wroclaw, 51-148 Wroclaw, Poland; (J.R.); (G.G.); (Z.D.-K.)
- Correspondence: ; Tel.: +48-71-375-6296
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9
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Lai YW, Pang CNI, Campbell LT, Chen SCA, Wilkins MR, Carter DA. Different Pathways Mediate Amphotericin-Lactoferrin Drug Synergy in Cryptococcus and Saccharomyces. Front Microbiol 2019; 10:2195. [PMID: 31632362 PMCID: PMC6779777 DOI: 10.3389/fmicb.2019.02195] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Accepted: 09/06/2019] [Indexed: 12/27/2022] Open
Abstract
Fungal infections are an increasing cause of morbidity and mortality. Current antifungal drugs are limited in spectrum, few new drugs are in development, and resistance is an increasing issue. Drug synergy can enhance available drugs and extend their lifetime, however, few synergistic combinations are in clinical use and mechanistic data on how combinations work is lacking. The multifunctional glycoprotein lactoferrin (LF) acts synergistically with amphotericin B (AMB) in a range of fungal species. Whole LF binds and sequesters iron, and LF can also be digested enzymatically to produce cationic peptides with distinct antimicrobial functions. To understand how LF synergizes AMB, we previously undertook a transcriptomic analysis in Saccharomyces and found a paradoxical down-regulation of iron and stress response, suggesting stress pathway interference was dysregulating an appropriate response, resulting in cell death. To extend this to a fungal pathogen, we here perform the same analysis in Cryptococcus neoformans. While both fungi responded to AMB in a similar way, the addition of LF produced remarkably contrasting results, with the Cryptococcus transcriptome enriched for processes relating to cellular stress, up-regulation of endoplasmic-reticulum-associated protein degradation (ERAD), stress granule disassembly and protein folding, endoplasmic reticulum-Golgi-vacuole trafficking and autophagy, suggesting an overall disruption of protein and lipid biosynthesis. These studies demonstrate that the mechanism of LF-mediated synergy is species-specific, possibly due to differences in the way LF peptides are generated, bind to and enter cells and act on intracellular targets, illustrating how very different cellular processes can underlie what appears to be a similar phenotypic response.
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Affiliation(s)
- Yu-Wen Lai
- School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW, Australia
| | - Chi Nam Ignatius Pang
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Kensington, NSW, Australia
| | - Leona T Campbell
- School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW, Australia
| | - Sharon C A Chen
- Marie Bashir Institute for Infectious Diseases and Biosecurity, The University of Sydney, Sydney, NSW, Australia.,Centre for Infectious Diseases and Microbiology, Institute of Clinical Pathology and Medical Research, Westmead Hospital, Sydney Medical School, The University of Sydney, Westmead, NSW, Australia
| | - Marc R Wilkins
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Kensington, NSW, Australia
| | - Dee A Carter
- School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW, Australia.,Marie Bashir Institute for Infectious Diseases and Biosecurity, The University of Sydney, Sydney, NSW, Australia
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Velliyagounder K, Bahdila D, Pawar S, Fine DH. Role of lactoferrin and lactoferrin‐derived peptides in oral and maxillofacial diseases. Oral Dis 2018; 25:652-669. [DOI: 10.1111/odi.12868] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Revised: 02/20/2018] [Accepted: 03/17/2018] [Indexed: 12/30/2022]
Affiliation(s)
- K Velliyagounder
- Department of Oral BiologyRutgers School of Dental Medicine Newark New Jersey
| | - D Bahdila
- Department of Oral BiologyRutgers School of Dental Medicine Newark New Jersey
| | - S Pawar
- Department of Oral BiologyRutgers School of Dental Medicine Newark New Jersey
| | - DH Fine
- Department of Oral BiologyRutgers School of Dental Medicine Newark New Jersey
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11
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Felipe LDO, Júnior WFDS, Araújo KCD, Fabrino DL. Lactoferrin, chitosan and Melaleuca alternifolia-natural products that show promise in candidiasis treatment. Braz J Microbiol 2018; 49:212-219. [PMID: 29132828 PMCID: PMC5913821 DOI: 10.1016/j.bjm.2017.05.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Revised: 04/03/2017] [Accepted: 05/26/2017] [Indexed: 02/06/2023] Open
Abstract
The evolution of microorganisms resistant to many medicines has become a major challenge for the scientific community around the world. Motivated by the gravity of such a situation, the World Health Organization released a report in 2014 with the aim of providing updated information on this critical scenario. Among the most worrying microorganisms, species from the genus Candida have exhibited a high rate of resistance to antifungal drugs. Therefore, the objective of this review is to show that the use of natural products (extracts or isolated biomolecules), along with conventional antifungal therapy, can be a very promising strategy to overcome microbial multiresistance. Some promising alternatives are essential oils of Melaleuca alternifolia (mainly composed of terpinen-4-ol, a type of monoterpene), lactoferrin (a peptide isolated from milk) and chitosan (a copolymer from chitin). Such products have great potential to increase antifungal therapy efficacy, mitigate side effects and provide a wide range of action in antifungal therapy.
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Affiliation(s)
| | | | | | - Daniela Leite Fabrino
- Universidade Federal de São João del-Rei/Campus Alto Paraopeba, Minas Gerais, MG, Brazil
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12
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Wang B, Timilsena YP, Blanch E, Adhikari B. Lactoferrin: Structure, function, denaturation and digestion. Crit Rev Food Sci Nutr 2017; 59:580-596. [DOI: 10.1080/10408398.2017.1381583] [Citation(s) in RCA: 126] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Bo Wang
- Food Research and Innovation Centre, School of Science, RMIT University, Melbourne, VIC, Australia
| | - Yakindra Prasad Timilsena
- Food Research and Innovation Centre, School of Science, RMIT University, Melbourne, VIC, Australia
- Materials Science and Engineering, CSIRO Manufacturing Flagship, Clayton South, VIC, Australia
| | - Ewan Blanch
- Food Research and Innovation Centre, School of Science, RMIT University, Melbourne, VIC, Australia
| | - Benu Adhikari
- Food Research and Innovation Centre, School of Science, RMIT University, Melbourne, VIC, Australia
- Materials Science and Engineering, CSIRO Manufacturing Flagship, Clayton South, VIC, Australia
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13
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Fernandes KE, Carter DA. The Antifungal Activity of Lactoferrin and Its Derived Peptides: Mechanisms of Action and Synergy with Drugs against Fungal Pathogens. Front Microbiol 2017; 8:2. [PMID: 28149293 PMCID: PMC5241296 DOI: 10.3389/fmicb.2017.00002] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Accepted: 01/03/2017] [Indexed: 11/13/2022] Open
Abstract
Lactoferrin is a multifunctional iron-binding glycoprotein belonging to the transferrin family. It is found abundantly in milk and is present as a major protein in human exocrine secretions where it plays a role in the innate immune response. Various antifungal functions of lactoferrin have been reported including a wide spectrum of activity across yeasts and molds and synergy with other antifungal drugs in combination therapy, and various modes of action have been proposed. Bioactive peptides derived from lactoferrin can also exhibit strong antifungal activity, with some surpassing the potency of the whole protein. This paper reviews current knowledge of the spectrum of activity, proposed mechanisms of action, and capacity for synergy of lactoferrin and its peptides, including the three most studied derivatives: lactoferricin, lactoferrampin, and Lf(1-11), as well as some lactoferrin-derived variants and modified peptides.
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Affiliation(s)
- Kenya E Fernandes
- School of Life and Environmental Sciences, University of Sydney Sydney, NSW, Australia
| | - Dee A Carter
- School of Life and Environmental Sciences, University of Sydney Sydney, NSW, Australia
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Zouhir A, Jridi T, Nefzi A, Ben Hamida J, Sebei K. Inhibition of methicillin-resistant Staphylococcus aureus (MRSA) by antimicrobial peptides (AMPs) and plant essential oils. PHARMACEUTICAL BIOLOGY 2016; 54:3136-3150. [PMID: 27246787 DOI: 10.1080/13880209.2016.1190763] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Revised: 04/21/2016] [Accepted: 05/12/2016] [Indexed: 06/05/2023]
Abstract
CONTEXT Drug-resistant bacterial infections cause considerable patient mortality and morbidity. The annual frequency of deaths from methicillin-resistant Staphylococcus aureus (MRSA) has surpassed those caused by human immunodeficiency virus/acquired immune deficiency syndrome. The antimicrobial peptides (AMPs), plant essential oils (EOs) and their combinations have proven to be quite effective in killing a wide selection of bacterial pathogens including MRSA. OBJECTIVES This review summarizes the studies in the use of AMPs, plant EOs and their combinations for coping with MRSA bacteria, and to formulate new prospects for future studies on this topic. METHODS The sources of scientific literature such as PubMed, library search, Google Scholar, Science Direct and electronic databases such as 'The Antimicrobial Peptide Database', 'Collection of Anti-Microbial Peptides' and 'YADAMP'. Physicochemical data of anti-MRSA peptides were determined by Scientific DataBase Maker software. RESULTS Of the 118 peptides, 88 exhibited an activity against MRSA with the highest activity of minimum inhibitory concentration values. Various plant EOs have been effective against MRSA. Remarkably, lemongrass EOs completely inhibited all MRSA growth on the plate. Lemon myrtle, Mountain savory, Cinnamon bark and Melissa EOs showed a significant inhibition. CONCLUSION Several of these AMPs, EOs and their combinations were effective against MRSA. Their activities have implications for the development of new drugs for medical use.
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Affiliation(s)
- Abdelmajid Zouhir
- a Nutraceuticals and Functional Proteomics Potential of Biodiversity in Tunisia, University of Tunis El Manar , El Manar , Tunisia
- b Research Unit at Institute of Applied Biological Sciences Tunis (ISSBAT) , Tunis , Tunisia
| | - Taoufik Jridi
- a Nutraceuticals and Functional Proteomics Potential of Biodiversity in Tunisia, University of Tunis El Manar , El Manar , Tunisia
- b Research Unit at Institute of Applied Biological Sciences Tunis (ISSBAT) , Tunis , Tunisia
| | - Adel Nefzi
- c Torrey Pines Institute for Molecular Studies , Port St. Lucie , FL , USA
| | - Jeannette Ben Hamida
- a Nutraceuticals and Functional Proteomics Potential of Biodiversity in Tunisia, University of Tunis El Manar , El Manar , Tunisia
- b Research Unit at Institute of Applied Biological Sciences Tunis (ISSBAT) , Tunis , Tunisia
| | - Khaled Sebei
- a Nutraceuticals and Functional Proteomics Potential of Biodiversity in Tunisia, University of Tunis El Manar , El Manar , Tunisia
- b Research Unit at Institute of Applied Biological Sciences Tunis (ISSBAT) , Tunis , Tunisia
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Lai YW, Campbell LT, Wilkins MR, Pang CNI, Chen S, Carter DA. Synergy and antagonism between iron chelators and antifungal drugs in Cryptococcus. Int J Antimicrob Agents 2016; 48:388-94. [PMID: 27474467 DOI: 10.1016/j.ijantimicag.2016.06.012] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Revised: 06/02/2016] [Accepted: 06/10/2016] [Indexed: 12/27/2022]
Abstract
Fungal infections remain very difficult to treat, and developing new antifungal drugs is difficult and expensive. Recent approaches therefore seek to augment existing antifungals with synergistic agents that can lower the therapeutic dose, increase efficacy and prevent resistance from developing. Iron limitation can inhibit microbial growth, and iron chelators have been employed to treat fungal infections. In this study, chequerboard testing was used to explore combinations of iron chelators with antifungal agents against pathogenic Cryptococcus spp. with the aim of determining how disruption to iron homeostasis affects antifungal susceptibility. The iron chelators ethylenediaminetetraacetic acid (EDTA), deferoxamine (DFO), deferiprone (DFP), deferasirox (DSX), ciclopirox olamine and lactoferrin (LF) were paired with the antifungal agents amphotericin B (AmB), fluconazole, itraconazole, voriconazole and caspofungin. All chelators except for DFO increased the efficacy of AmB, and significant synergy was seen between AmB and LF for all Cryptococcus strains. Addition of exogenous iron rescued cells from the antifungal effect of LF alone but could not prevent inhibition by AmB + LF, indicating that synergy was not due primarily to iron chelation but to other properties of LF that were potentiated in the presence of AmB. Significant synergy was not seen consistently for other antifungal-chelator combinations, and EDTA, DSX and DFP antagonised the activity of azole drugs in strains of Cryptococcus neoformans var. grubii. This study highlights the range of interactions that can be induced by chelators and indicates that most antifungal drugs are not enhanced by iron limitation in Cryptococcus.
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Affiliation(s)
- Yu-Wen Lai
- School of Life and Environmental Sciences, University of Sydney, Sydney, NSW, Australia
| | - Leona T Campbell
- School of Life and Environmental Sciences, University of Sydney, Sydney, NSW, Australia
| | - Marc R Wilkins
- Systems Biology Initiative, School of Biotechnology and Biomolecular Sciences, University of New South Wales, Kensington, NSW, Australia
| | - Chi Nam Ignatius Pang
- Systems Biology Initiative, School of Biotechnology and Biomolecular Sciences, University of New South Wales, Kensington, NSW, Australia
| | - Sharon Chen
- Centre for Infectious Diseases and Microbiology Laboratory Services, ICPMR, Westmead Hospital and the University of Sydney, Sydney, NSW, Australia
| | - Dee A Carter
- School of Life and Environmental Sciences, University of Sydney, Sydney, NSW, Australia.
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Significant antibacterial activity and synergistic effects of camel lactoferrin with antibiotics against methicillin-resistant Staphylococcus aureus (MRSA). Res Microbiol 2016; 167:480-91. [DOI: 10.1016/j.resmic.2016.04.006] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Revised: 04/05/2016] [Accepted: 04/11/2016] [Indexed: 11/20/2022]
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Trivedi A, Maheshwari R, Tarnow-Mordi WO, Saxena N. Lactoferrin for the post-operative management of term neonates after gastrointestinal surgery. Hippokratia 2016. [DOI: 10.1002/14651858.cd012218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Amit Trivedi
- The Children's Hospital at Westmead; Grace Centre for Newborn Care; Westmead NSW Australia 2145
| | - Rajesh Maheshwari
- Westmead Hospital; Department of Neonatology; 807/91B Bridge Road Westmead NSW Australia 2145
| | - William O Tarnow-Mordi
- Westmead Hospital; Department of Neonatal Medicine; Corner of Hawksberry and Darcy Road Westmead NSW Australia 2145
| | - Nivedita Saxena
- Ulster Hospital; Paediatric Department; Upper Newtownards Road Belfast UK BT16 1RH
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Mora-Navarro C, Caraballo-León J, Torres-Lugo M, Ortiz-Bermúdez P. Synthetic antimicrobial β-peptide in dual-treatment with fluconazole or ketoconazole enhances the in vitro inhibition of planktonic and biofilm Candida albicans. J Pept Sci 2015; 21:853-61. [PMID: 26470850 DOI: 10.1002/psc.2827] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Revised: 09/05/2015] [Accepted: 09/09/2015] [Indexed: 11/06/2022]
Abstract
Fungal infections are a pressing concern for human health worldwide, particularly for immunocompromised individuals. Current challenges such as the elevated toxicity of common antifungal drugs and the emerging resistance towards these could be overcome by multidrug therapy. Natural antimicrobial peptides, AMPs, in combination with other antifungal agents are a promising avenue to address the prevailing challenges. However, they possess limited biostability and susceptibility to proteases, which has significantly hampered their development as antifungal therapies. β-peptides are synthetic materials designed to mimic AMPs while allowing high tunability and increased biostability. In this work, we report for the first time the inhibition achieved in Candida albicans when treated with a mixture of a β-peptide model and fluconazole or ketoconazole. This combination treatment enhanced the biological activity of these azoles in planktonic and biofilm Candida, and also in a fluconazole-resistant strain. Furthermore, the in vitro cytotoxicity of the dual treatment was evaluated towards the human hepatoma cell line, HepG2, a widely used model derived from liver tissue, which is primarily affected by azoles. Analyses based on the LA-based method and the mass-action law principle, using a microtiter checkerboard approach, revealed synergism of the combination treatment in the inhibition of planktonic C. albicans. The dual treatment proved to be fungicidal at 48 and 72 h. Interestingly, it was also found that the viability of HepG2 was not significantly affected by the dual treatments. Finally, a remarkable enhancement in the inhibition of the highly azole-resistant biofilms and fluconazole resistant C. albicans strain was obtained.
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Affiliation(s)
- Camilo Mora-Navarro
- Department of Chemical Engineering, University of Puerto Rico, Mayagüez Campus, Mayagüez, 00680, Puerto Rico
| | - Jean Caraballo-León
- Department of Chemical Engineering, University of Puerto Rico, Mayagüez Campus, Mayagüez, 00680, Puerto Rico
| | - Madeline Torres-Lugo
- Department of Chemical Engineering, University of Puerto Rico, Mayagüez Campus, Mayagüez, 00680, Puerto Rico
| | - Patricia Ortiz-Bermúdez
- Department of Chemical Engineering, University of Puerto Rico, Mayagüez Campus, Mayagüez, 00680, Puerto Rico
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Trend S, Strunk T, Hibbert J, Kok CH, Zhang G, Doherty DA, Richmond P, Burgner D, Simmer K, Davidson DJ, Currie AJ. Antimicrobial protein and Peptide concentrations and activity in human breast milk consumed by preterm infants at risk of late-onset neonatal sepsis. PLoS One 2015; 10:e0117038. [PMID: 25643281 PMCID: PMC4314069 DOI: 10.1371/journal.pone.0117038] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Accepted: 12/17/2014] [Indexed: 12/13/2022] Open
Abstract
Objective We investigated the levels and antimicrobial activity of antimicrobial proteins and peptides (AMPs) in breast milk consumed by preterm infants, and whether deficiencies of these factors were associated with late-onset neonatal sepsis (LOS), a bacterial infection that frequently occurs in preterm infants in the neonatal period. Study design Breast milk from mothers of preterm infants (≤32 weeks gestation) was collected on days 7 (n = 88) and 21 (n = 77) postpartum. Concentrations of lactoferrin, LL-37, beta-defensins 1 and 2, and alpha-defensin 5 were measured by enzyme-linked immunosorbent assay. The antimicrobial activity of breast milk samples against Staphylococcus epidermidis, Staphylococcus aureus, Escherichia coli, and Streptococcus agalactiae was compared to the activity of infant formula, alone or supplemented with physiological levels of AMPs. Samples of breast milk fed to infants with and without subsequent LOS were compared for levels of AMPs and inhibition of bacterial growth. Results Levels of most AMPs and antibacterial activity in preterm breast milk were higher at day 7 than at day 21. Lactoferrin was the only AMP that limited pathogen growth >50% when added to formula at a concentration equivalent to that present in breast milk. Levels of AMPs were similar in the breast milk fed to infants with and without LOS, however, infants who developed LOS consumed significantly less breast milk and lower doses of milk AMPs than those who were free from LOS. Conclusions The concentrations of lactoferrin and defensins in preterm breast milk have antimicrobial activity against common neonatal pathogens.
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Affiliation(s)
- Stephanie Trend
- Centre for Neonatal Research and Education, University of Western Australia, Perth, Western Australia, Australia
- School of Paediatrics and Child Health, University of Western Australia, Perth, Western Australia, Australia
| | - Tobias Strunk
- Centre for Neonatal Research and Education, University of Western Australia, Perth, Western Australia, Australia
- School of Paediatrics and Child Health, University of Western Australia, Perth, Western Australia, Australia
- Neonatal Clinical Care Unit, King Edward Memorial Hospital for Women, Perth, Western Australia, Australia
| | - Julie Hibbert
- School of Paediatrics and Child Health, University of Western Australia, Perth, Western Australia, Australia
| | - Chooi Heen Kok
- Centre for Neonatal Research and Education, University of Western Australia, Perth, Western Australia, Australia
- Neonatal Clinical Care Unit, King Edward Memorial Hospital for Women, Perth, Western Australia, Australia
| | - Guicheng Zhang
- School of Public Health, Curtin University, Perth, Australia
| | - Dorota A. Doherty
- School of Women’s and Infants’ Health, University of Western Australia, Perth, Australia
| | - Peter Richmond
- School of Paediatrics and Child Health, University of Western Australia, Perth, Western Australia, Australia
| | - David Burgner
- Murdoch Childrens Research Institute, Parkville, Victoria, Australia
- University of Melbourne, Melbourne, Victoria, Australia
| | - Karen Simmer
- Centre for Neonatal Research and Education, University of Western Australia, Perth, Western Australia, Australia
- School of Paediatrics and Child Health, University of Western Australia, Perth, Western Australia, Australia
- Neonatal Clinical Care Unit, King Edward Memorial Hospital for Women, Perth, Western Australia, Australia
| | - Donald J. Davidson
- The University of Edinburgh/MRC Centre for Inflammation Research, Queen’s Medical Research Institute, Edinburgh, United Kingdom
| | - Andrew J. Currie
- Centre for Neonatal Research and Education, University of Western Australia, Perth, Western Australia, Australia
- School of Paediatrics and Child Health, University of Western Australia, Perth, Western Australia, Australia
- School of Veterinary and Life Sciences, Murdoch University, Perth, Western Australia, Australia
- * E-mail:
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Sharma D, Murki A, Murki S, Pratap OT. Use of lactoferrin in the newborn: where do we stand? J Matern Fetal Neonatal Med 2014; 28:1774-8. [PMID: 25245229 DOI: 10.3109/14767058.2014.968548] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Sepsis and necrotizing enterocolitis (NEC) cause significant morbidity and mortality in the newborn. Their ill effects persist in spite of appropriate and effective antibiotic therapy. Lactoferrin as an adjunct to antibiotics in the treatment of sepsis or NEC in the newborn may improve the clinical outcomes by enhancing the host defense and modulating the inflammatory response. This review focuses on the various aspects of lactoferrin use in the newborn.
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Affiliation(s)
- Deepak Sharma
- a Department of Neonatology , Fernandez Hospital , Hyderguda , Hyderabad , Andhra Pradesh , India and
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Interplay between Candida albicans and the antimicrobial peptide armory. EUKARYOTIC CELL 2014; 13:950-7. [PMID: 24951441 DOI: 10.1128/ec.00093-14] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Antimicrobial peptides (AMPs) are key elements of innate immunity, which can directly kill multiple bacterial, viral, and fungal pathogens. The medically important fungus Candida albicans colonizes different host niches as part of the normal human microbiota. Proliferation of C. albicans is regulated through a complex balance of host immune defense mechanisms and fungal responses. Expression of AMPs against pathogenic fungi is differentially regulated and initiated by interactions of a variety of fungal pathogen-associated molecular patterns (PAMPs) with pattern recognition receptors (PRRs) on human cells. Inflammatory signaling and other environmental stimuli are also essential to control fungal proliferation and to prevent parasitism. To persist in the host, C. albicans has developed a three-phase AMP evasion strategy, including secretion of peptide effectors, AMP efflux pumps, and regulation of signaling pathways. These mechanisms prevent C. albicans from the antifungal activity of the major AMP classes, including cathelicidins, histatins, and defensins leading to a basal resistance. This minireview summarizes human AMP attack and C. albicans resistance mechanisms and current developments in the use of AMPs as antifungal agents.
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Lactoferrin for prevention of neonatal sepsis. Biometals 2014; 27:1007-16. [PMID: 24935001 DOI: 10.1007/s10534-014-9754-3] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2014] [Accepted: 05/27/2014] [Indexed: 01/13/2023]
Abstract
Preterm neonates are at risk to acquire infections. In addition to the high mortality associated with sepsis, these patients are at risk for long-term disabilities, particularly neurodevelopment impairment. Several interventions have been evaluated to reduce rates of infections in neonates but have not proven efficacy. Lactoferrin (LF), a milk glycoprotein with anti-inflammatory, immunomodulatory and anti-microbial properties, has the potential to prevent infections in young children. We performed a review of current and ongoing clinical trials of LF for prevention of neonatal sepsis, and found eleven registered clinical trials that include more than 6,000 subjects. Few of these trials have finished; despite their small sample size, the preliminary results show a trend towards a positive protective effect of LF on neonatal infections. Larger trials are underway to confirm the findings of these initial studies. This information will help to define LF's role in clinical settings and, if proven effective, would profoundly affect the treatment of low birth weight neonates as a cost-effective intervention worldwide.
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Combination of fluconazole with non-antifungal agents: A promising approach to cope with resistant Candida albicans infections and insight into new antifungal agent discovery. Int J Antimicrob Agents 2014; 43:395-402. [DOI: 10.1016/j.ijantimicag.2013.12.009] [Citation(s) in RCA: 94] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2013] [Revised: 12/18/2013] [Accepted: 12/19/2013] [Indexed: 12/29/2022]
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UPC2 is universally essential for azole antifungal resistance in Candida albicans. EUKARYOTIC CELL 2014; 13:933-46. [PMID: 24659578 DOI: 10.1128/ec.00221-13] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
In Candida albicans, the transcription factor Upc2 is central to the regulation of ergosterol biosynthesis. UPC2-activating mutations contribute to azole resistance, whereas disruption increases azole susceptibility. In the present study, we investigated the relationship of UPC2 to fluconazole susceptibility, particularly in azole-resistant strains. In addition to the reduced fluconazole MIC previously observed with UPC2 disruption, we observed a lower minimum fungicidal concentration (MFC) for a upc2Δ/Δ mutant than for its azole-susceptible parent, SC5314. Moreover, the upc2Δ/Δ mutant was unable to grow on a solid medium containing 10 μg/ml fluconazole and exhibited increased susceptibility and a clear zone of inhibition by Etest. Time-kill analysis showed higher fungistatic activity against the upc2Δ/Δ mutant than against SC5314. UPC2 disruption in strains carrying specific resistance mutations also resulted in reduced MICs and MFCs. UPC2 disruption in a highly azole resistant clinical isolate containing multiple resistance mechanisms likewise resulted in a reduced MIC and MFC. This mutant was unable to grow on a solid medium containing 10 μg/ml fluconazole and exhibited increased susceptibility and a clear zone of inhibition by Etest. Time-kill analysis showed increased fungistatic activity against the upc2Δ/Δ mutant in the resistant background. Microarray analysis showed attenuated induction by fluconazole of genes involved in sterol biosynthesis, iron transport, or iron homeostasis in the absence of UPC2. Taken together, these data demonstrate that the UPC2 transcriptional network is universally essential for azole resistance in C. albicans and represents an attractive target for enhancing azole antifungal activity.
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Lingappan K, Arunachalam A, Pammi M. Lactoferrin and the newborn: current perspectives. Expert Rev Anti Infect Ther 2014; 11:695-707. [PMID: 23879609 DOI: 10.1586/14787210.2013.811927] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Neonatal sepsis and necrotizing enterocolitis (NEC) are associated with significant mortality and morbidity. Inflammation secondary to sepsis and NEC increases morbidity, especially those related to the lung, brain and eye. Therapeutic strategies that target inflammation and decrease the emergence of antibiotic resistance are urgently needed. Lactoferrin (Lf) is a multifunctional protein that modulates inflammation, cell growth and differentiation and has broad antimicrobial activity. Studies evaluating the efficacy and safety of Lf in the prevention of neonatal sepsis and NEC are currently in progress, and one completed study shows significant promise. In this article, the functions of this multifunctional molecule and current clinical evidence for its use in the newborn are reviewed. Lf prophylaxis and therapy may have a significant impact in improving clinical outcomes of vulnerable preterm neonates.
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Affiliation(s)
- Krithika Lingappan
- Section of Neonatology, Department of Pediatrics, Texas Children's Hospital & Baylor College of Medicine, Houston, TX 77030, USA
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Reeves AA, Johnson MC, Vasquez MM, Maheshwari A, Blanco CL. TGF-β2, a protective intestinal cytokine, is abundant in maternal human milk and human-derived fortifiers but not in donor human milk. Breastfeed Med 2013; 8:496-502. [PMID: 23869537 PMCID: PMC3919475 DOI: 10.1089/bfm.2013.0017] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
OBJECTIVE This study compared cytokines (in particular transforming growth factor [TGF]-β2) and lactoferrin in maternal human milk (MHM), human-derived milk fortifier (HDMF), and donor human milk (DHM). MATERIALS AND METHODS MHM was randomly collected from breastfeeding mothers who had no infectious illness at the time of milk expression. HDMF and DHM were products derived from human milk processed by Holder pasteurization. MHM samples were collected at different times (early/late) and gestations (preterm/term). Lactoferrin was analyzed by western blotting, and cytokines were quantified using commercial enzyme-linked immunosorbent assays. Significance was determined using analysis of variance. RESULTS In the 164 samples analyzed, TGF-β2 concentrations in HDMF and preterm MHM (at all collection times) were fivefold higher than in DHM (p<0.05). Early preterm MHM had levels of interleukin (IL)-10 and IL-18, 11-fold higher than DHM (p<0.05). IL-6 in DHM was 0.3% of the content found in MHM. IL-18 was fourfold higher in early MHM versus late MHM regardless of gestational age (p<0.05). Lactoferrin concentration in DHM was 6% of that found in MHM. CONCLUSIONS Pasteurization decreases concentrations of most cytokines and lactoferrin in DHM. TGF-β2, a protective intestinal cytokine, has comparable concentrations in HDMF to MHM despite pasteurization.
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Affiliation(s)
- Aaron A Reeves
- 1 Division of Neonatology, Department of Pediatrics, University of Texas Health Science Center , San Antonio, Texas
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Xu ZQ, Flavin MT, Flavin J. Combating multidrug-resistant Gram-negative bacterial infections. Expert Opin Investig Drugs 2013; 23:163-82. [PMID: 24215473 DOI: 10.1517/13543784.2014.848853] [Citation(s) in RCA: 96] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
INTRODUCTION Multidrug-resistant (MDR) bacterial infections, especially those caused by Gram-negative pathogens, have emerged as one of the world's greatest health threats. The development of novel antibiotics to treat MDR Gram-negative bacteria has, however, stagnated over the last half century. AREAS COVERED This review provides an overview of recent R&D activities in the search for novel antibiotics against MDR Gram-negatives. It provides emphasis in three key areas. First, the article looks at new analogs of existing antibiotic molecules such as β-lactams, tetracyclines, and aminoglycoside as well as agents against novel bacterial targets such as aminoacyl-tRNA synthetase and peptide deformylase. Second, it also examines alternative strategies to conventional approaches including cationic antimicrobial peptides, siderophores, efflux pump inhibitors, therapeutic antibodies, and renewed interest in abandoned treatments or those with limited indications. Third, the authors aim to provide an update on the current clinical development status for each drug candidate. EXPERT OPINION The traditional analog approach is insufficient to meet the formidable challenge brought forth by MDR superbugs. With the disappointing results of the genomics approach for delivering novel targets and drug candidates, alternative strategies to permeate the bacterial cell membrane, enhance influx, disrupt efflux, and target specific pathogens via therapeutic antibodies are attractive and promising. Coupled with incentivized business models, governmental policies, and a clarified regulatory pathway, it is hoped that the antibiotic pipeline will be filled with an effective armamentarium to safeguard global health.
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Affiliation(s)
- Ze-Qi Xu
- SynChem, Inc. , 1400 Chase Avenue, Elk Grove Village, IL 60007 , USA +1 847 298 2436 ;
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Embleton ND, Berrington JE, McGuire W, Stewart CJ, Cummings SP. Lactoferrin: Antimicrobial activity and therapeutic potential. Semin Fetal Neonatal Med 2013; 18:143-149. [PMID: 23507150 DOI: 10.1016/j.siny.2013.02.001] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Lactoferrin is a highly conserved protein from an evolutionary perspective, with a wide range of roles related to protection from infection and promotion of nutritional status. Infection, malnutrition and intestinal pathologies are key inter-related problems, represent important threats to survival and are associated with adverse long-term health outcomes after preterm birth. Lactoferrin is available as a commercial extract from bovine milk and offers potential as a therapeutic intervention for preterm infants modulating infections and intestinal pathologies. In this review we explore the structure, direct antimicrobial effects, modification of host immune function and gastrointestinal effects of lactoferrin. Current trial data are reviewed, and research priorities and challenges identified and discussed.
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Affiliation(s)
- Nicholas D Embleton
- Newcastle Neonatal Service, Newcastle upon Tyne Hospitals NHS Foundation Trust, Queen Victoria Road, Newcastle upon Tyne NE1 4LP, UK; Institute of Health and Society, Newcastle University, Newcastle upon Tyne, UK.
| | - Janet E Berrington
- Newcastle Neonatal Service, Newcastle upon Tyne Hospitals NHS Foundation Trust, Queen Victoria Road, Newcastle upon Tyne NE1 4LP, UK; Institute of Health and Society, Newcastle University, Newcastle upon Tyne, UK
| | - William McGuire
- National Institute for Health Research, Centre for Reviews and Dissemination, University of York, York, UK
| | - Chris J Stewart
- School of Life Sciences, University of Northumbria, Newcastle upon Tyne, UK
| | - Stephen P Cummings
- School of Life Sciences, University of Northumbria, Newcastle upon Tyne, UK
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Neonatal immune adaptation of the gut and its role during infections. Clin Dev Immunol 2013; 2013:270301. [PMID: 23737810 PMCID: PMC3659470 DOI: 10.1155/2013/270301] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2013] [Accepted: 04/03/2013] [Indexed: 12/22/2022]
Abstract
The intestinal tract is engaged in a relationship with a dense and complex microbial ecosystem, the microbiota. The establishment of this symbiosis is essential for host physiology, metabolism, and immune homeostasis. Because newborns are essentially sterile, the first exposure to microorganisms and environmental endotoxins during the neonatal period is followed by a crucial sequence of active events leading to immune tolerance and homeostasis. Contact with potent immunostimulatory molecules starts immediately at birth, and the discrimination between commensal bacteria and invading pathogens is essential to avoid an inappropriate immune stimulation and/or host infection. The dysregulation of these tight interactions between host and microbiota can be responsible for important health disorders, including inflammation and sepsis. This review summarizes the molecular events leading to the establishment of postnatal immune tolerance and how pathogens can avoid host immunity and induce neonatal infections and sepsis.
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Abstract
Medically relevant biofilms have gained a significant level of interest, in part because of the epidemic rise in obesity and an aging population in the developed world. The associated comorbidities of chronic wounds such as pressure ulcers, venous leg ulcers, and diabetic foot wounds remain recalcitrant to the therapies available currently. Development of chronicity in the wound is due primarily to an inability to complete the wound healing process owing to the presence of a bioburden, specifically bacterial biofilms. New therapies are clearly needed which specifically target biofilms. Lactoferrin is a multifaceted molecule of the innate immune system found primarily in milk. While further investigation is warranted to elucidate mechanisms of action, in vitro analyses of lactoferrin and its derivatives have demonstrated that these complex molecules are structurally and functionally well suited to address the heterogeneity of bacterial biofilms. In addition, use of lactoferrin and its derivatives has proven promising in the clinic.
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Affiliation(s)
- M C Ammons
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT, USA.
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Kotsaki A, Giamarellos-Bourboulis EJ. Emerging drugs for the treatment of sepsis. Expert Opin Emerg Drugs 2012; 17:379-91. [PMID: 22780561 DOI: 10.1517/14728214.2012.697151] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
INTRODUCTION Despite improvement in medical care, severe sepsis and septic shock remain an unmet medical need. Their incidence is steadily increasing and the worldwide mortality ranges between 30% and 50%. This generates the need for agents that modulate the immune function of the host. AREAS COVERED Available agents can be divided into three categories according to their mechanism of action: i) agents that block bacterial products and inflammatory mediators. Hemoperfusion with polymyxin B embedded fiber device that blocks bacterial lipopolysaccharides (LPS) has given promising clinical results. Blockade of TNF-α with afelimomab and CytoFab appears promising; ii) modulators of immune function. Hydrocortisone stress replacement, intravenous infusion of clarithromycin and immunonutrition with omega-3 (ω-3) polyunsaturated fatty acids (PUFAs) have all yielded positive clinical results. Recombinant thrombomodulin for patients with disseminated intravascular coagulation appears a promising alternative; and iii) immunostimulation. Meta-analysis of conducted trials disclosed the decrease of mortality in septic shock after administration of immunoglobulin preparations enriched with IgM. EXPERT OPINION The underlying pathophysiologic mechanisms in septic patients are highly individualized. As such, specific tools should be developed in the near future to define these differences and tailor therapeutic strategies accordingly.
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Affiliation(s)
- Antigone Kotsaki
- University of Athens, Medical School, 4th Department of Internal Medicine, Athens, Greece
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Ortíz-Estrada G, Luna-Castro S, Piña-Vázquez C, Samaniego-Barrón L, León-Sicairos N, Serrano-Luna J, de la Garza M. Iron-saturated lactoferrin and pathogenic protozoa: could this protein be an iron source for their parasitic style of life? Future Microbiol 2012; 7:149-64. [PMID: 22191452 DOI: 10.2217/fmb.11.140] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Iron is an essential nutrient for the survival of pathogens inside a host. As a general strategy against microbes, mammals have evolved complex iron-withholding systems for efficiently decreasing the iron accessible to invaders. Pathogens that inhabit the respiratory, intestinal and genitourinary tracts encounter an iron-deficient environment on the mucosal surface, where ferric iron is chelated by lactoferrin, an extracellular glycoprotein of the innate immune system. However, parasitic protozoa have developed several mechanisms to obtain iron from host holo-lactoferrin. Tritrichomonas fetus, Trichomonas vaginalis, Toxoplasma gondii and Entamoeba histolytica express lactoferrin-binding proteins and use holo-lactoferrin as an iron source for growth in vitro; in some species, these binding proteins are immunogenic and, therefore, may serve as potential vaccine targets. Another mechanism to acquire lactoferrin iron has been reported in Leishmania spp. promastigotes, which use a surface reductase to recognize and reduce ferric iron to the accessible ferrous form. Cysteine proteases that cleave lactoferrin have been reported in E. histolytica. This review summarizes the available information on how parasites uptake and use the iron from lactoferrin to survive in hostile host environments.
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Affiliation(s)
- Guillermo Ortíz-Estrada
- Departamento de Biología Celular, Centro de Investigación y de Estudios Avanzados del IPN, Apdo. 14-740, México DF 07000, México
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Barboza M, Pinzon J, Wickramasinghe S, Froehlich JW, Moeller I, Smilowitz JT, Ruhaak LR, Huang J, Lönnerdal B, German JB, Medrano JF, Weimer BC, Lebrilla CB. Glycosylation of human milk lactoferrin exhibits dynamic changes during early lactation enhancing its role in pathogenic bacteria-host interactions. Mol Cell Proteomics 2012; 11:M111.015248. [PMID: 22261723 DOI: 10.1074/mcp.m111.015248] [Citation(s) in RCA: 116] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Human milk lactoferrin (hmLF) is the most abundant glycoprotein present in human milk and displays a broad range of protective functions in the gut of newborn infants. hmLF is N-glycosylated, but little is known about the lactation stage-related development of the glycosylation phenotype. hmLF glycosylation from milk samples from five donors during the first 10 weeks of lactation was assessed and observed to be more diverse than previously reported. During this period dynamic changes in glycosylation were observed corresponding to a decrease in glycosylation in the second week followed by an increase in total glycosylation as well as higher order fucosylation thereafter. Gene expression analysis was performed in milk somatic cells from a sixth subject. It was found that fucosyltransferase expression increased during entire period, whereas expression of genes for the oligosaccharyl transferase complex decreased in the second week. The effect of hmLF glycosylation was examined for the protein's ability to affect bacterial binding to epithelial cells. hmLF significantly inhibited pathogen adhesion and purified hmLF glycans significantly reduced Salmonella invasion of colonic epithelial cells to levels associated with non-invasive deletion mutants. This study indicates that hmLF glycosylation is tightly regulated by gene expression and that glyco-variation is involved in modulating pathogen association.
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Affiliation(s)
- Mariana Barboza
- Department of Chemistry, Functional Glycobiology Program, University of California Davis. One Shields Ave, Davis, California 95616, USA
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Brouwer CPJM, Rahman M, Welling MM. Discovery and development of a synthetic peptide derived from lactoferrin for clinical use. Peptides 2011; 32:1953-63. [PMID: 21827807 DOI: 10.1016/j.peptides.2011.07.017] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2011] [Revised: 07/22/2011] [Accepted: 07/22/2011] [Indexed: 01/11/2023]
Abstract
There is an urgent need to develop new antimicrobial drugs especially for combating the rise of infections caused by multi-resistant pathogens such as MRSA and VRSA. The problem of antibiotic resistant micro-organisms is expected to increase disproportionally and controlling of infections is becoming difficult because of the rapid spread of those micro-organisms. Primary therapy with classical antibiotics is becoming more ineffective. Combinational therapy of antibiotics with antimicrobial peptides (AMP's) has been suggested as an alternative approach to improve treatment outcome. Their unique mechanism of action and safety profile makes AMP's appealing candidates for simultaneous or sequential use in different cases of infections. In this review, for antimicrobial treatment the application of synthetic antimicrobial peptide hLF(1-11), derived from the first 11 amino acids of human lactoferrin is evaluated in both pre-clinical and clinical settings. Present information indicates that this derivate from lactoferrin is well tolerated in pre-clinical tests and clinical trials and thus hLF(1-11) is an interesting candidate for further exploration in various clinical indications of obscure infections, including meningitis. Another approach of using AMP's is their use in prevention of infections e.g. as coating for dental or bone implants or in biosensing applications or useful as infection specific radiopharmaceutical.
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Affiliation(s)
- Carlo P J M Brouwer
- Department of Radiology, Section of Nuclear Medicine, Leiden University Medical Center, Room C4-R-77, Leiden, The Netherlands
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Linder N, Hernandez A, Amit L, Klinger G, Ashkenazi S, Levy I. Persistent coagulase-negative staphylococci bacteremia in very-low-birth-weight infants. Eur J Pediatr 2011; 170:989-95. [PMID: 21221994 DOI: 10.1007/s00431-010-1387-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/19/2010] [Accepted: 12/20/2010] [Indexed: 11/26/2022]
Abstract
This study sought to expand current knowledge on the clinical and epidemiological characteristics of persistent coagulase-negative Staphylococcus (CoNS) bacteremia in very-low-birth-weight (VLBW) infants. Background and disease-related data were collected prospectively on 143 VLBW infants diagnosed with CoNS bacteremia at a pediatric tertiary medical center in 1995-2003. Findings were compared between those with persistent (positive blood cultures for >72 h under appropriate treatment ) and nonpersistent disease. Fifty-eight infants (40.6%) were found to have persistent bacteremia. There were no between-group differences in maternal characteristics, mode of delivery, newborn characteristics, dwell time of central venous and umbilical catheters, complications of prematurity, or mean hospital stay. The persistent bacteremia group had significantly higher rates of hypothermia at presentation (37.9% vs. 17.6%, p < 0.04), creatinine >1.2 mg% on treatment day 7 (13.7% vs. 2.4%, p < 0.02; transient phenomenon), and endocarditis (p < 0.03); one infant had an aortic thrombus. Predominantly breast-fed infants had a higher rate of negative cultures within 72 h of appropriate treatment than predominantly formula-fed infants (60% vs. 19%, p < 0.02). In conclusion, persistence of CoNS bacteremia is common in VLBW infants. Endocarditis should be excluded in all infants with persistent disease. Breast-feeding is associated with a shorter disease duration.
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Affiliation(s)
- Nehama Linder
- Department of Neonatology, Rabin Medical Center, 2 Denmark St, Petach Tikva, 49100, Israel.
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Conesa C, Calvo M, Sánchez L. Recombinant human lactoferrin: A valuable protein for pharmaceutical products and functional foods. Biotechnol Adv 2010; 28:831-8. [DOI: 10.1016/j.biotechadv.2010.07.002] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2010] [Revised: 06/14/2010] [Accepted: 07/04/2010] [Indexed: 10/19/2022]
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Abstract
The role of endotoxin in the genesis of sepsis has long been recognized and multiple treatments aimed at neutralizing it have been studied. Endotoxin can be bound by antibodies (whose role as a therapeutic agent is unlikely), binding proteins such as BPI or human lactoferrin (effectiveness debated and promising respectively) and phospholipid emulsion (which has not improved outcomes in a recent study). Alternatively, the action of endotoxin could be blocked by lipid A analogs (initial study showed no overall benefit and another large trial is near completion targeting a subpopulation of that study). Finally, endotoxin can be bound by polymyxin B embedded in hemoperfusion cartridges. The later treatment has been used for more than a decade in Japan. Since both pre-clinical rationale and studies support the targeting of endotoxin to ameliorate the pro-inflammatory and pro-coagulation response of severe sepsis, this therapeutic intervention is being pursued.
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Deykin AV, Ermolkevich TG, Gursky YG, Krasnov AN, Georgieva SG, Kuznetsov SL, Derevyanko VG, Novikova NI, Murashev AN, Goldman IL, Sadchikova ER. The state of health and the reproductive potential of transgenic mice secreting recombinant human lactoferrin in milk. DOKL BIOCHEM BIOPHYS 2009; 427:195-8. [PMID: 19817135 DOI: 10.1134/s1607672909040073] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- A V Deykin
- Institute of Gene Biology, Russian Academy of Sciences, ul. Vavilova 34/5, Moscow 119334, Russia
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Role of ferroxidases in iron uptake and virulence of Cryptococcus neoformans. EUKARYOTIC CELL 2009; 8:1511-20. [PMID: 19700638 DOI: 10.1128/ec.00166-09] [Citation(s) in RCA: 104] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Iron acquisition is a critical aspect of the virulence of many pathogenic microbes, and iron limitation is an important defense mechanism for mammalian hosts. We are examining mechanisms of iron regulation and acquisition in the fungal pathogen Cryptococcus neoformans, and here, we characterize the roles of the ferroxidases Cfo1 and Cfo2. Cfo1 is required for the reductive iron uptake system that mediates the utilization of transferrin, an important iron source for C. neoformans during infection. The virulence of a cfo1 mutant was attenuated in a mouse model of cryptococcosis, and the mutant also displayed increased sensitivities to the antifungal drugs fluconazole and amphotericin B. Wild-type levels of drug sensitivity were restored by the addition of exogenous heme, which suggested that reduced levels of intracellular iron may curtail heme levels and interfere with ergosterol biosynthesis. We constructed green fluorescent protein (GFP) fusion proteins and found elevated expression of Cfo1-GFP upon iron limitation, as well as localization of the fusion to the plasma membrane. Trafficking to this location was disrupted by a defect in the catalytic subunit of cyclic AMP-dependent protein kinase. This result is consistent with findings from studies indicating an influence of the kinase on the expression of protein-trafficking functions in C. neoformans.
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Venkatesh M, Rong L, Raad I, Versalovic J. Novel synergistic antibiofilm combinations for salvage of infected catheters. J Med Microbiol 2009; 58:936-944. [PMID: 19502361 DOI: 10.1099/jmm.0.009761-0] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Biofilms on catheters are responsible for catheter-related bloodstream infections (CRBSIs), which cause significant mortality and morbidity. Antimicrobial catheter-lock solutions may salvage precious catheters by eradicating biofilms. Staphylococcus epidermidis and Candida albicans are frequently isolated organisms in CRBSIs. We evaluated N-acetylcysteine (NAC), EDTA, ethanol and talactoferrin (TLF) individually and in combination with antibiotics against biofilms of S. epidermidis and C. albicans to identify effective catheter-lock solutions. Minimum biofilm-eradication concentrations causing 50% inhibition (MBEC(50)) for EDTA, NAC, ethanol and TLF were determined against biofilms of S. epidermidis and C. albicans formed on 96-well microtitre plates. Biomass, mean thickness and viability of S. epidermidis and C. albicans biofilms were evaluated after exposure to MBEC(50) concentrations of EDTA, NAC, ethanol and TLF. Antimicrobial combinations of EDTA, NAC, ethanol and TLF with nafcillin, vancomycin, fluconazole and amphotericin B were evaluated systematically for synergy using combination indices (CIs). EDTA, NAC, ethanol and TLF significantly reduced biofilm biomass and mean thickness (P<0.05, one-way ANOVA) of monomicrobial and polymicrobial biofilms as evaluated by confocal microscopy. CIs evaluated at equipotency ratios, and 50, 75 and 90 % effects, showed that EDTA, NAC, ethanol and TLF were synergistic (CI <1) with antibiotics (with few exceptions) against biofilms of S. epidermidis and C. albicans. EDTA, NAC, ethanol and TLF inhibit monomicrobial and polymicrobial biofilms of neonatal strains of S. epidermidis and C. albicans, and are synergistic with antibiotics. Catheter-lock solutions of EDTA, NAC and ethanol alone or in combination with antibiotics may be used to salvage infected catheters, which will directly impact on patient morbidity and health-care costs.
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Affiliation(s)
- Mohan Venkatesh
- Section of Neonatology, Department of Pediatrics, Texas Children's Hospital & Baylor College of Medicine, Houston, TX 77030, USA
| | - Liang Rong
- Section of Neonatology, Department of Pediatrics, Texas Children's Hospital & Baylor College of Medicine, Houston, TX 77030, USA
| | - Issam Raad
- Department of Infectious Diseases, MD Anderson Cancer Center, Houston, TX 77030, USA
| | - James Versalovic
- Department of Pathology, Texas Children's Hospital & Baylor College of Medicine, Houston, TX 77030, USA
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